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With recent indications that bugs and fish are exposed to 39,700 parts per billion of copper plus lead, arsenic, cadmium, and zinc beyond federal benchmarks in the “last second mile” of Silver Bow Creek, some say it deserves more attention.

From the confluence at George Street until roughly Ranchland Packing on Centennial Avenue, the creek journeys through a heart muscle of Butte’s industrial past, flowing along walls of rough-hewn, black layers of poured smelter waste. Bluish-green striations in the black layers indicate copper leaching through.

Above it is an old smelter site called Butte Reduction Works, or the BRW. What’s left there is a place where no tree or blade of grass grows. It’s as bald and baked as the sun. Mounds of different-colored soils and gravels blend in with parts and pieces of historic smelting fixtures that were never torn down, current county-owned equipment, industrial debris, and piles of junk. There are a couple of small white tanks containing contaminated groundwater collected at the site sitting in one corner close to South Montana St.

Jon Sesso, county Superfund coordinator, said this is likely the most challenging part of what Atlantic Richfield Company still has to remediate on the Butte Hill. In addition to the metals, there is hydrocarbon pollution, likely from diesel fuel, which will complicate removing the "dirty dirt."

But one day, the same 20 acres could have trees, grass, shrubs and trails. The concrete elements still standing from the site's smelter days — parts of the base of the old smelter stack and a giant, concrete ore bin — could remain in place as historic features. It could have an amphitheater where residents can rock on to music in the fine blue dusk of a summer evening. Michael Abendhoff, Atlantic Richfield’s Chicago-based spokesperson, said through email that the amphitheater would be “funded and constructed by Atlantic Richfield Company.”

It will likely still have the slag walls — a sheer drop off along the northern part of the new park — but the creek will no longer flow down below. Instead, a walking trail could replace it.

Silver Bow Creek, instead, will gurgle and attract visitors to the south side of the new park.

“It’s going to be pretty cool to come off the interstate and look down and see the reconstructed stream all the way down,” Nikia Greene, EPA project manager for the Butte Hill said recently. “It’s going to be pretty cool.”

It will likely be in a lined, straightened channel for a short distance before returning to its natural curves past some industrial sites — Ranchland Packing, Metro Sewer and the large ponds called the Butte Treatment Lagoons — as it wends its way to Whiskey Gulch trailhead. That is a popular spot and the beginning of the $23 million Greenway Trail that is supposed to one day enable amblers to traverse parts of two counties.

All that stands in the way of this vision are the John Hancocks of the negotiating parties on the consent decree on Aug. 12.

This portion of the park would be the tail end of the proposed 120 acres that Atlantic Richfield would reclaim.

So far, the proposed plan for this part of the park, and the creek, has received little to no public criticism or commentary.  But some at the state worry that the plans to keep contaminated groundwater from reaching the newly reconstructed stream won’t be enough to protect the state’s $157 million investment it made when it cleaned up lower Silver Bow Creek in recent years.

What’s at stake?

When the state started its work on lower Silver Bow Creek in 1999, the toxicity was so bad from historic mining and smelting, fish hadn’t appeared in the creek in over 100 years. While lower Silver Bow Creek hasn't fully rebounded, it has improved enough for fish to be found there.

About a mile away from Silver Bow Creek's bank, the state has been excavating mine and smelting waste from 120 years ago, the Parrot tailings, for the last year.

At the heart of the state’s argument for why that long-ago buried pollution needed to be removed, instead of capped, was to protect the state's investment in the lower 26-mile stretch of creek.

Jim Ford, Natural Resource Damage Program environmental science specialist, said the NRD made excavation of the hazardous stuff behind the Butte Civic Center a priority a few years ago because the Environmental Protection Agency did not agree that the "dirty dirt" needed to be taken out.

But, Ford said, the biggest threat to the creek is not what was buried at the old Parrot Smelter. The biggest danger, he said, is the BRW site because it sits right along Silver Bow Creek.

How bad the "dirty dirt" is there is unknown to all but Atlantic Richfield, Ford said. The state did some sampling in 2016, but he said the state faced limitations on how much sampling it could do.

But, one thing that is known is the history of the site, which gives pause to some, such as Ford, who have overseen the removal of around 400,000 cubic yards of material at the old Parrot Smelter. 

Workers from the old Parrot Smelter bought the BRW soon after it began production in the 1880s. Ford thinks it's likely that the damage done to the land and the groundwater at the BRW will be similar. Also, the BRW ran a little longer than the Parrot Smelter did.

In addition, even after the BRW closed as a copper smelter in 1910, the Anaconda Mining Company leased it to a company called Domestic Manganese, which processed manganese there until about the end of World War II. It then became a phosphorous plant. The Anaconda Mining Co. tore down the stack in the 1970s.

Another thing that the state knows is that the worst contamination found in the stream bed and bank along Silver Bow Creek is in the Slag Wall Canyon. Officials all seem to agree that there are likely tailings — mine waste — buried underneath the slag walls.

Atlantic Richfield says it doesn't want to disturb the slag walls through the canyon because they have value as historical structures.

Although Atlantic Richfield is planning to relocate the creek to the south side of the old BRW, it will still be within 275 feet of all that lies below and will remain beneath the new park.

That's because the former oil giant will remove the pollution up to 275 feet from the newly built creek on the south side of the old BRW site. The rest of the long buried contamination will be left in place.

The EPA and Atlantic Richfield are counting on an engineered barrier — officials call it “a control” — to prevent groundwater from flowing through all the polluted material and then reaching the creek.

What that will look like is one of the many nitty-gritty details that have yet to emerge from the process of getting a finalized cleanup plan. But one option Atlantic Richfield is considering is a horizontal pipe that has openings in it. It will be buried underground. At one end will be a pump to suck in the “dirty” water beneath the soils like a horizontal straw.

Butte already has such a slotted pipe to catch contaminated groundwater. It’s called the subdrain, or the reverse French drain, as some in the community refer to it. It lies underneath upper Silver Bow Creek from Texas Avenue to George Street.

The current subdrain is unpopular with many creek advocates in Butte.

It’s not often that a piece of engineered hydraulic equipment buried out of sight should be the centerpiece of so much anger and anguish, but both the state and the community have long argued that the current subdrain fails to capture all of the contaminated groundwater along upper Silver Bow Creek. Currently, upper Silver Bow Creek is a straightened channel that captures run off from storms through the center of town. 

Ford said the state prefers a system with wells that go vertically into the ground, not a pipe that lays horizontally.

Greene said "nothing is set in stone." But he also said that while EPA believes wells that dive vertically in the ground are "better" than a subdrain at controlling the groundwater flowing toward the creek, a subdrain has not been ruled out by the EPA.

"If during design it proves that a subdrain is more effective, then we would propose that," he said.

But, Ford said a subdrain will not do the job intended.

“A subdrain only controls horizontal flows,” Ford said. “The current subdrain (underneath upper Silver Bow Creek) is not an adequate control. If we thought it could adequately control the groundwater, the state wouldn’t have removed the Parrot.”

Although Atlantic Richfield insists it only needs to be cleaned out twice a year, Fritz Daily, long-time Superfund activist, says he sees a contractor cleaning the subdrain out far more often than that.

Ford said the NRD sees evidence from monitoring wells through the upper Silver Bow Creek corridor that appears to indicate Atlantic Richfield’s contractor is cleaning it out more often than twice a year.

Whatever system Atlantic Richfield and the EPA decide upon, it will remain in place “as long as necessary to meet cleanup goals,” said Josh Bryson, BP operations project manager. BP owns Atlantic Richfield.

Atlantic Richfield has a range as to how long that will be. It could be as short a time as 10 years, Bryson said.

But it could be as long as 500 years, Bryson said.

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Nat'l Resources / General Reporter

Environmental and natural resources reporter for the Montana Standard.

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